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w. H. HOWARD. PROCESS OF DISCHARGING SMELTER GASES.

'APPUCATION FILED MAR. 8, 1921.

Patented July 11, 1922.

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s ares stares WILLIAM H. HOWARD, OF SALT Lfijiiili v CITY, UTAH,ASSIGNOR TO AMERICAN SMELT- ING- AND REFINING COMPANY, OF NEW YORK, N.Y., A CORPORATION OF NEW JEIMSEY.

Application filed March a, 1921. Serial No.

To all whom it may concern:

Be it known that 1, WILLIAM H. HOWARD, a citizen of the United States,and resident of Salt Lake City, in the county of Salt Lake and State ofUtah, have invented certain new and useful Improvements in Processes ofDischarging Smelter Gases, of which the following is a specification.

The invention relates in general to an improvemcnt in the method andapparatus for handling obnoxious gases in the act of dis charging suchgases into the atmospheric air, and specifically relates to an improvement in the method of discharging into the air those gases which aredeleterious to vegetable and animal life, such for instance as thesulphur dioxide fumes discharged in certain smelting and othermetallurgical operations.

It is well known that considerable difficulty has been experienced inmetallurgical plants to insure the discharge of sulphurdioxide andsimilar fumes in such a way that these gases will be diffused in theupper regions of the atmospheric air and accordingly diluted to such anextent that they will not be harmful should they be forced back to theground by prevailing atmospheric conditions.

It is understood that these gases come off of the furnaces at extremelyhigh temperatures and it is usual to pass the gasesintohigh chimneystacks but this is not entirely satisfactory and there is, of course, alimit in the height to which these stacks can be built.

One of the objects of the invention tis to provide a simple, easilypracticed and economical method for dischargingobnoxious gases in such away as will minimize their tendency to damage vegetable and animal life.v

The invention contemplates the subjecting of these gases while confinedin the usual high chimney stack to such a treatment as will cause themto lose in a large measure their obnoxious characteristics even beforethey are discharged, and finally to discharge them from the stack insuch a way as will cause the column of gas to bore through theatmosphere above the discharge end of the stack and thus confine thegases evenin the absence of a continuation of the stack. This columnarform has the effect of holding the gases in a closely projected streamuntil they Specification of Letters Patent. i

point for the gases.

PROCESS OF DISCHARGING- SHELTER GASES.

Patented July 11, 1922.

reach a material height above the high stack, and in this way thedischarging act tends to increase the possibility of the obnoxious gasesbeing so diluted before they can reach the ground that their obnoxiouscharacter will have entirely disappeared.

Broadly, I attain this object by introducing into the stack, adjacentits base, air or some other diluting and unobjectionable gas in avolumetric sufiiciency to supply an excessive amount of inoffensive gascapable of mixing with and highly diluting the obnoxious gases, andpreferably by so heating these diluting gases to a temperature equal toor even in excess of the temperature of the obnoxious gases, and inmaintaining contact between the gases for the whole length of the stackso that all the gases present are discharged at high nozzle velocity andcapable of boring through the upper air spaces before the column ofgases is diffused in the Considering the apparatus features of thedisclosure, an object of the invention is to provide a simple form ofinstrumentality for effectively and efficiently practicing the aboveoutlined method and in which the chimney element features a dischargenozzle construction to increase the far-reaching effect of thedischarged gas column.

Referring to the accompanying drawing which will be utilized indescribing one preferred method of practicing the invention, there isshown in diagrammatic outline the discharge stack of a metallurgicalfurnace equipped with an auxiliary gas heater illustrating a preferredembodiment of. the apparatus feature of the disclosure.

In the drawings there is shown diagrammatically at 10 the dischargeconduit of a conventional form of smelting furnace which is dischargingobnoxious gases, such as sulphur dioxide, into a stack 11. This stack isof conventional'form, and while not necessary to the practicing of theinvention herein disclosed, is preferably of the high type so as to takeadvantage of the long heating space provided by such a high stack and totake advantage of the usual high discharge The invention comprises theprojective force of the gases in the present disclosure to attain an.additional height over the present high point discharges from suchchimney stacks.

A supplemental gas heating unit indicated at 12 is disposed ad'acent thebase of the stack and discharges y means of an upwardlyinclinedconduit13 into the base of the stack but it is to be understood thatthis supplemental heating unit is otherwise independent of the furnaceand its stack.

In the present disclosure air is passed aperature, it is suggestedthatte air may be forced under pressure through the heater 'and into thestack and for thethis purpose *there is illustrated a blower 14 of anyconventional form. While reference has been made to the member 12 as anair heater it, is

-to be understood that its products of combustion may be dischargeddirectly into "the conduit l3 and thus add to the air discharged.

In operation and assuming that the furnace is functioning as usual,discharging-its sulphur dioxide and other obnoxious gases into the tallchimney stack, the air heater is started and, if necessary, the bloweris set in operation. The air and products of combustion are quickly andintensely heated and passed into the stack. The hot air is thus broughtinto intimate contact, mixing with the obnoxious gases and by the timethe mixture has reached the top of the stack the gases havebeenthoroughly diffused one in the otherand in this way the obnoxiousgases are diluted even before they are dischar ed from the stack.

Anot er action is going on during this mixing operation. The heat of thehot air is imparted to the obnoxious gases so that the'mixturein thestack may be even at a higher temperature than the obnoxious gasesdischarged into the bottom of the stack and the result is that themixture travels at high velocity through and out of the stack.

It has been observed that when leaving the stack the gases maintaintheir columnar effect and, possibly due to the converging nozzle shapetop of the stack, the upper portion of thev gas column appears tocontract. The eifect of this forceful propulsion is to hold the gasestogether, and they do not spread out immediately after leaving thestack. On the contrary the column ofgases rise above the stack in asolid as stream for several hundred feet in e ect borin a hole throughthe atmospheric layers. ibove the constricted portion the gases begin tospread out'into a mushroom-effect and are quietly and slowly dissipatedinto the air.

It has been found in the vicinity of plants in which this method ispracticed that the blightingefiect on vegetation heretofore known haspractically dlsappeared, and the objections heretofore present todischarging such obnoxious gases even out of the usual high stack havedisappeared. The method is economical for in some plants a suitablesource of waste heat is usually available, and in other plantscombustible gasis available for the heater, and in an case the onlyadditional cost is in the lnstallation and maintenance of the air heaterfor supplying the hot diluting air to the stack.

While I have shown and described and have pointed out in the annexedclaims, certain novel features of my invention, it will be understoodthat various omissions, substitutions and chan es in the form anddetails of the device i'l ustrated and in its operation, may be made bythosewskilled in the art without departing from the spirit of theinvention.

Having thus described my invention, I claim:

1. In the art of safely discharging into the air, furnace gases whichare obnoxious or harmful to vegetation or animal life, the method whichconsists in discharging such gases into a chimney or similar conduitextending highinto the air, and simultaneously discharging into thechimney so as to mix thoroughly with the obnoxious gases thereima gas ofan unobjectionable character having a temperature higher than thetemperature of the atmosphere and in a volume sufficient to mix with andthus dilute the obnoxious gases to-an extent such that the mixtureformed in=the chimney will readily diffuse into the atmosphere and byextreme dilution of the obnoxious gases therein have its objectionablecharacteris tics reduced before it can come in contact with vegetationin the vicinity.

2. In the art of safely discharging into the air hot furnace gaseshaving an obnoxious character, the method which consists in causing thehot gases to move upwardly under their inherent draft through a chimneyor similar conduit discharging at its upper end into the air anddirecting intosaid chimney a current of hot of an unobjectionablecharacter, said d1 uting gases having a temperature not materially lessthan the temconduit a hot gas free of obnoxious characteristics,maintaining the contact for a period of time sufficient to admit of athorough mixing of the gases before they are dis charged into the air,and thus diluting the obnoxious gases, said diluting gas having anamount of heat per unit volume, suflicient in the presence of theadjacent obnoxious gas to maintain its own conductivity withoutimpairing the rate of propulsion inherent in the hot obnoxious gases.

4c. In the art of discharging obnoxious gases, the method which includesa two-step diluting treatment, and comp-rises first, subjecting theobnoxious gases, While confined, to a mixing therewith of other gasescapable when combined therewith of minimizing the objectionable effectsof the obnoxious gases, and then as the second step, the projecting ofthe mixture forcefully high into the air and permitting it to spread outin a mushroom shape and thus become diffused in the upper atmosphere.

5. In the art of discharging gases containing sulphur dioxide into theatmosphere, the method which consists in heating the gases as they aredischarged into a chimney to form an ascending column whereby they arecaused to move rapidly and forcefully up the chimney, introducing hotair into the lower portions of the gas: column maintaining contactbetween the air and gas for a period of time sufiicient to permit of athorough mixing of the two gases and thus insure a complete dilution ofthe sulphur dioxide gases, said hot air having a temperature notmaterially less than the temperature of the sulphur dioxide gaseswhereby the introduction of the diluting air will not impair thedischarging efficiency of the hot sulphur dioxide gases.-

6. In a device for diffusing obnoxious gases high into the air, thecombination of a chimney stack extending into the air, means for heatingsaid gases as they are discharged into the stack, and means independ entof said heating means and opening into the lower portion of the stackfor supplying a hot diluting gas to the gases in the stack whereby thehot obnoxious gases and the hot diluting gases are caused to mix beforethe obnoxious gases are discharged into the air.

7 In a device for diffusing obnoxious gases, the combination of a highchimney stack converging towards its discharge end to form agas-projecting nozzle, means for feeding the obnoxious gases while hotto said stack, and means for feeding other gases while hot to saidobnoxious gases to dilute and heat the same, said nozzle acting on thehot gases discharged therefrom toproject the same in a relatively closedcolumn high in the air before they begin to disperse.

8. In a metallurgical plant the co1nbination of a high chimney stack forreceiving the obnoxious gases delivered from smelting furnaces and thelike, a separate gas heating outfit discharging into said stack heat-edgases capable of commingling with the obnoxious gases in the stackduring their passage therethrough and thus insuring the forcefuldischarge of said gases high in the air.

Signed at Pasadena, in the county of Los Angeles and State ofCalifornia, this 22 day of February, A. D. 1921.

WILLIAM H. HOWARD.

